German Patent Publication DE 38 18 292 A1 relates to a process for the preparation of fatty acid or hydroxy fatty acid esters of isopropylidene derivatives of a polyglycerol from fatty acid alkyl esters, mono- or polyhydroxy fatty acid alkyl esters having C.sub.6 -C.sub.22 in the fatty acid component and C.sub.1 -C.sub.4 in the ester components, which are reacted in an alkaline medium with one or more isopropylidene derivatives of a polyglycerol. The reaction is carried out at temperatures from 140 to 220.degree. C. and in vacuo at 5 to 950 mbar. The C.sub.1 -C.sub.4 alcohol formed in this reaction is removed by distillation and the reaction product is purified. Furthermore, the use of the fatty acid or hydroxy fatty acid esters of mono- and/or diisopropylidene derivatives of polyglycerol prepared in this way as intermediates for the preparation of nonionic surfactants, as solvents or solubilizers and for cosmetic preparations and skin care agents is described.
European Publicatin EP 0 383 405 A1 describes a process for the preparation of esters by reaction of a C.sub.7 -C.sub.36 mono- or dicarboxylic acid and a C.sub.2 -C.sub.8 monoalcohol in the presence of a lipase catalyst, the water of reaction being removed from the C.sub.2 -C.sub.8 monoalcohol and water by azeotropic distillation of the mixture. In particular, the azeotropic distillation of the alcohol and the addition of the alcohol are carried out simultaneously at the same rate under reduced pressure. The process can be carried out in a one-pot system at a temperature below 80.degree. C. The esterification and the azeotropic distillation can also be carried out in separate reaction vessels, in which higher temperatures and higher pressures can be used.
European Publication EP 0 451 461 B1 describes the use of mixtures of polyglycerol fatty acid esters as emulsifiers in cosmetic and pharmaceutical preparations. These are obtainable by partial esterification of polyglycerols with at least one saturated fatty acid having 12 to 22 C atoms or at least one unsaturated fatty acid having 16 to 22 C atoms, where the unsaturated fatty acid or fatty acid mixture employed can additionally contain up to 10% by weight of saturated fatty acids having 16 to 22 C atoms. The degree of esterification of the saturated or unsaturated fatty acids in the mixture is between 20 and 70%.
German Patent Publication DE 44 07 015 C2 relates to cosmetic and/or pharmaceutical preparations which, as emulsifiers, contain esters of palmitic acid with technical triglycerides with the proviso that the content of monoesters is 30 to 50% by weight.
European Publication EP 0 093 602 A2 describes a transesterification by means of a lipase enzyme system as a transesterification catalyst. In a continuous transesterification process, a fatty acid derivative, in particular a glycerol, which optionally contains free fatty acid, is brought into contact with an enzyme as a transesterification catalyst, which is preferably 1,3-selective and is immobilized on an inert particulate carrier. The catalyst is packed in a solid bed and remains in contact with the reaction mixture for less than 2 hours. The process is particularly suitable for the preparation of POSt- and StOSt-rich fats, which are suitable as a cocoa butter substitute (P here stands for palmitate, O for oleate and St for stearate).
International Publication WO 90/09451 describes fatty acid esters of methyl glycosides which are obtained by reaction of a fatty acid or of a fatty acid ester with a methyl glycoside in the presence of an enzyme catalyst, in particular of a lipase. The resulting fatty acid esters are preferably monoesters. Methyl glycoside fatty acid esters can be employed as surface-active agents in cleansing agents or cosmetic agents.